I'm trying to work out how best to locate the centroid of an arbitrary shape draped over a unit sphere, with the input being ordered (clockwise or anti-cw) vertices for the shape boundary. The density ...

I would like to try and show data such that it appears as if it was on google earth. For example, in this case, the view of the earth is circular-like and the data shown curves around. Are there any ...

I'm trying to find the concave hull of a lat, lon pointset but when I project my points on my map it doesn't look like expected. I've tried a lineare projection and a spherical projection. My data is ...

I need to draw a line between two points and create a buffer around this line. The only difficulty is that I need to draw not a "cartesian" line but a line that is laying on the spheroid.
I tried to ...

So my problem is that I have start point [lat,long] for arch, bearing, radius and I need compute end point [lat,long] ? End point should be in 180 degrees angle from start point and I should be aware ...

First, sorry if this questions sound very simple. I am very new to GIS.
Given four values of north/south latitude, east/west longitude how to calculate the center point that is correct for all cases ...

Can anyone help me what's the algorythm to calculate points of intersection whet is given one point p1 [lat,long] , bearing x (let say 137 degrees), arc center [lat,long] and radius?
I woulde like to ...

I've got a little problem.
I have a GPX-Track containing LatLon coordinates based on WGS84. The track should be drawn on a cropped map, and for this, I need the pixel coordinates. The map tiles are ...

I have a line formed by 2 lat/lon pairs, and the lat/lon of a point. I would like to find out the perpendicular distance between the line and the point on the Earth surface (can assume Earth as great ...

I have a line (Ax,Ay - Bx,By) over a mercator projection (google maps) and a random point (Cx,Cy) nearest to that line, i would to know the closest point (transparent blue on the image) over that line ...

Suppose I already have a way to compute the centroids of different geometry types:
Points (arithmetic mean of Cartesian coordinates).
Linestrings (polylines) (weighted mean of segment mid-points in ...

There are many papers on the "Circle Placement Problem" in 2D Euclidean space, but I haven't been able to find any papers discussing this problem on the sphere. The problem is: given a set of points ...

I am trying to make a figure showing azimuthal data with a different range of uncertainties at each point. This oldschool figure from a 1991 paper captures the "bowtie plot" idea that I'm aiming for:
...

I have a simple array (not geo-referenced in any way) in Matlab (which is not a language I know a huge amount about...so I can export it to other languages if needed) which has the dimensions 180 x ...

I'm trying to draw a circle with OpenLayers with a Google Maps Layer. I'm able to transform a simple marker and have it draw at the correct location, but I can't figure out the circle. I'm trying to ...

There are few ways of articulating my question. It starts with a known circle on a sphere, i.e. a point-radius, and one that does not cover a pole. I would like to calculate the point furthest west ...

I'm working on implementing the OSM Mobile Binary format for map data, and because it uses a 16 bit delta for each point along a way, it cannot represent a way if there is a large distance between two ...

My question is related to this:
http://stackoverflow.com/questions/7927863/location-data-format-for-adehabitat-package
I have a relational database with 'world tiles'. Each tile has a side length of ...